1. Field of the Invention
This invention relates to chrysoberyl solid state lasers and more particularly it relates to such lasers which are provided with a laser medium consisting of chrysoberyl (BeAl.sub.2 O.sub.4) single crystal containing trivalent titanium ions as luminescent ions, an excitation light emission means, an excitation light focussing means and a light resonator and in which the directions of crystal axes of the chrysoberyl single crystal constituting said laser medium are specified.
2. Description of the Prior Art
Solid state lasers are being increasingly used in various industrial fields because of their small size, high output power, easy maintenance and excellent stability.
Among the solid state lasers, those having trivalent titanium ions as luminescent ions are expected to be used in various fields since they can be tuned so that they oscillate to produce a wavelength over a continuous and extremely wide range. Among others, chrysoberyl single crystals doped with trivalent titanium ions have been proposed for use as very promising solid state lasers media as described in U.S. Pat. No. 4,765,925 which corresponds to Japanese Pat. Appln. Laid-Open Gazette No. Sho.62-216286 assigned to the same assignee as the present application. This single crystal has a wide absorption band, the center of wavelengths of which is 500 nm, it emits light in a wide region of from 600 nm to over 950 nm, and wavelength-variable solid state lasers having wavelength tunability in the above wide region are expected to be realized.
Further, the present inventors have also proposed a solid state laser in which excitation light emitted from a source of excitation light is focussed on the laser medium with a focussing lens and then luminescent ions are excited in the laser medium thereby to emit oscillated laser light. This solid state lasers, however, is not satisfactory in size, output etc.
This invention was made in view of the above circumstances.
The primary object of this invention is to provide chrysoberyl solid state lasers which are further improved in energy efficiency over the above conventional lasers.